qBittorrent Jackett Search Plugin

Modified version:
https://raw.githubusercontent.com/brianrianrehan/search-plugins/refs/heads/patch-1/nova3/engines/jackett.py

Change:
Added a browser-like User-Agent header to urllib requests to prevent
HTTP 403 Forbidden responses from Jackett.

Original source:
https://github.com/qbittorrent/search-plugins/blob/master/nova3/engines/jackett.py